Mapping thermal and hydrological conditions beneath a polythermal glacier with radio-echo sounding

Distinct bacterial communities exist beneath a high Arctic polythermal glacier.

Bacterial communities reside in basal ice, sediment, and meltwater in the supra-, sub-, and proglacial environments of John Evans Glacier, Nunavut, Canada. We examined whether the subglacial bacterial community shares common members with the pro- and supraglacial communities, and by inference, whether it could be derived from communities in either of these environments (e.g., by ice overriding ...

Radio frequency Echo mapping with cellular devices

In this paper, a method is presented that employs portable cellular devices to perform three-dimensional localization of metallic objects from a set of time-delayed signals. These signals are observed by an array of receiving elements having arbitrary and a priori known distributions in space. Widely used solutions for direction finding are based on Time of Arrival (TOA) measurements. The measu...

Radio Echo Sounding of the Greenland Inland Ice

Radio echo sounding has been used for a number of years in the exploration of polar ice such as the inland ice in Greenland and Antarc­ tica. By means of this technique a number of important glaciological and geophysical parameters may be deter­ mined. Examples are ice thickness, bedrock topography and structure, stratification patterns which are used for climate and flow patterns studies, and ...

Multi-decadal reduction in glacier velocities and mechanisms driving deceleration at polythermal White Glacier, Arctic Canada

Annual and seasonal surface velocities measured continuously from 1960 to 1970 at White Glacier, a 14 km long polythermal valley glacier spanning∼100–1800 m a.s.l., provide the most comprehensive early record of ice dynamics in the Canadian Arctic. Through comparison with differential GPSderived velocity data spanning 2012–16, we find reductions in mean annual velocity by 31 and 38% at lower el...

Mapping subglacial surfaces of temperate valley glaciers by two-pass migration of a radio-echo sounding survey